Both Nikons should do fine, but you may find the 9.3 degrees of the 7x easier for the larger objects.

I use 7x42's with an 8.6 degree field for Milky Way cruising and find it much better than the 8x binos I also had. With the 9,3 degrees you will be able to see context and asterisms much better than with the 8 degree field. Anything bigger than ca. 8.5 degrees will do very well for your intended viewing.

Some of your past endorsements for your 7x42 Dialyts contributed to me embarking on the same route. Absolutely wonderful experience cruising the Milky Way with my Zeiss FL 7x42's. Tried to find a nice pair of the Dialyt version but did not succeed, so settled on the new Victory FL's after a few months. Delightful binos. Such an involving, bright relaxing view. Unsurpassed for the MilkyWay!

I have a pair of those Nikon 7x35 but they're not my first choice for viewing the Milky Way's bright and dark nebulosity. Of the binoculars I have, I actually get the best views with my 15x60. More detail, better contrast, you get the picture.

If I had regular access to pristine skies I would own a pair of 10.5x70 for this particular purpose. I had a 7x50 in the past and for viewing dark nebulosity, the large exit pupil does deliver quality views. I would not go both to a smaller exit pupil and to a smaller aperture.

For panning the milkyway in general I like the blue planet 2.3x40 Galilean opera glasses (advertised 28 deg TFOV and near zero eye relief). 2nd choice 7x40 Orion UW 14 deg FOV. Neither are made in the US anymore. Vixen Ascot 8x50mm UW are pretty god too for handholding.

For panning the milkyway in general I like the blue planet 2.3x40 Galilean opera glasses (advertised 28 deg TFOV and near zero eye relief). 2nd choice 7x40 Orion UW 14 deg FOV. Neither are made in the US anymore. Vixen Ascot 8x50mm UW are pretty god too for handholding.

I have the 7x32 Orion Expanse with 14 deg FOV but did not know there was a 7x40 version made in the US . When were they made in the US ?

I agree with Mark, a really great view with a 10x70! I have the Nikon 10x70 6.5 degree field and it is absolutely immersive for sweeping the Milky Way and a lot of dark nebula like Barnard's "E" near Altair just pop in these and the area just off the spout of Sagittarius' teapot is amazingly textured.

Way more impressive than my 9.3 degree Nikon 7x35 or Celestron 7x50 Nova.

As can be divined, there is no one perfect binocular. For any task. Ask 10 people and you'll get at least 9 different recommendations. And any one person's tastes are almost guaranteed to evolve, too!

For the Milky Way, the widest field at the selected magnification is desirable. You must first decide what magnification and exit pupil you like. The aperture follows.

For a first bino for this task, 7-8X will serve well. Personally, I'm quite happy to suffer soft imagery toward the field edge if it buys me more field of view. My argument? If for a wide angle bino the central 50 degrees is as good as that for a narrower field bino, that extra outer field, even if aberrated, is a bonus! After all, with a hand held instrument you have no need to gaze toward the field edge. Let your lower resolution, highly sensitive outer retina utilize the outer field.

For such a vast object as the milky way, you'll appreciate a large apparent field.

I have a pair of those Nikon 7x35 but they're not my first choice for viewing the Milky Way's bright and dark nebulosity. Of the binoculars I have, I actually get the best views with my 15x60. More detail, better contrast, you get the picture.

If I had regular access to pristine skies I would own a pair of 10.5x70 for this particular purpose. I had a 7x50 in the past and for viewing dark nebulosity, the large exit pupil does deliver quality views. I would not go both to a smaller exit pupil and to a smaller aperture.

I have a pair of 11x80's that are by far the best binocs I have for deep sky viewing, but for wide field views of the Milky Way, my little Nikon 7x35's do better. Different tools for different jobs...
Marty

For the Milky Way, the widest field at the selected magnification is desirable. You must first decide what magnification and exit pupil you like. The aperture follows.

For a first bino for this task, 7-8X will serve well. Personally, I'm quite happy to suffer soft imagery toward the field edge if it buys me more field of view. My argument? If for a wide angle bino the central 50 degrees is as good as that for a narrower field bino, that extra outer field, even if aberrated, is a bonus! After all, with a hand held instrument you have no need to gaze toward the field edge. Let your lower resolution, highly sensitive outer retina utilize the outer field.

For such a vast object as the milky way, you'll appreciate a large apparent field.

I couldn't agree more. Though I'm still looking for the "perfect night sky scanning" binocular. I've always been partial to my Super-Wide 7x35s, but recently I've purchased 3 Super-Wide angle 7x50s just to see what they might do for me (other than add weight!)

My own thinking is that there is no one best binocular, best scope, for viewing the Milky Way. The Milky Way has many scales, there are large scale details that may not be visible in a 1.6 degree TFoV but there are somewhat smaller scale details that will be visible in that 12 inch scope with the 1.6 degree TFoV but not seen in a pair of binoculars with a 9 degree TFoV.

For a given true field of view, the highest magnification, largest exit pupil is best... This translates into the largest aperture with the widest AFoV. Mel Bartel's 13 inch scope is F/3.3 and with a Paracorr and a 21mm Ethos provides a 1.9 degree TFoV.

Given the choice of an aberrated outer field or no outer field at all I would take the aberrated outer field every time. Wouldn't you?

Graham

Graham:

Not really.. there is a point at which the edge aberrations become distracting, when a bright star is such a mess that it bears no resemblance to a round point or dot, when a brighter field star is obviously astigmatic and a dim field star disappears.

These extreme widefields are the result of short focal length objectives and most often simple eyepiece designs pushed to the limit so in the outer field you have the combination of astigmatism from the eyepiece and field curvature from the objective.

My calculation for the field curvature at the edge of a pair of 7x35s with a 10 degree TFoV is 1.6mm, that's based on an F/4 objective. At F/4 this means the blur is 0.4mm at the focal plane and will be magnified 7x... And we are not using Naglers here to handle the astigmatism.

There is a point where I find a narrower field of view is preferable. In this situation, since the aperture and field of view are open, I generally choose a somewhat larger binocular that is better corrected, probably due to a smaller amount of field curvature over an ulta wide field design.

The larger binocular can have the same generous AFoV but reduced aberrations.

I simply couldn't afford extremely wide angle binos with a perfectly flat field. Given that reality, I love my cheaper wide angle 7x35's. Would a perfectly flat field be better? Sure, but the SLIGHTLY distorted field is much better than nothing.Marty

What is the best binocular for viewing the milky way, the overall structure with star and dark clouds from a dark site ( 21.5 mag/arcsec^2) ?

with many thanks in advance

Thomas

For scanning activities from a very dark site I like my 8x40s to see structure. The variety of shades and patterns of dark and bright nebula seem to really stand out. They feel good in the hand, they're a comfortable weight and give me a nice and steady view.

I like "perfect" images and really wide AFovs. Regardless magnification, my three preferred binoculars give me that, the Docters giving considerably more Afov at the expense of aperture...Mounted not very portable: Fujinon 40x150EDMounted but portable: Docter Aspectem 40x80EDHandheld: Swarovision 8x32 and SW 10x42EL

For what I've read, the Kowa Prominar 32x82 softness in the edge is not distracting, so they may well be also in the second cathegory (soon), but really distorted edges are unacceptable to me... I'm in the smaller group that would choose a near perfect edge/small Afov over the opposite.